I am working on a house right now and we are trying to figure out what to do with the backyard. Right behind the house there is a 4" concrete pad. It is about 14'x25' and sits pretty flat with a slight dip out - so water is not building up on it. This was put together with concrete trimmings on two outer edges that supported posts that have been removed. The concrete trim areas are 1.5' wide.
The inside concrete is in OK shape. The external 1.5' trim areas are rough, very rough. I could skim the whole thing and it might look good for a year or two but I doubt it would last. Also even with a new coating I just don't think the pad fits the yard.
So the yard is coming down at about a 5% grade to the house - just a big sloped yard. At about 15 feet from the house the yard flattens until you leave the front porch and continues down. So this concrete is saving the house from some water hitting it directly.
Right in front of the patio is a drainage ditch (just a few inches) and a french drain system that goes to the side of the house - note that the patio is only about 1/2 the width of the house.
My idea is to build a raised deck - about 1-1.5' high that goes until it hits the slope which would probably be at 20' with a 6" step off. I have built front porch decking over concrete but have not done anything this large before. Are there any concerns you would have, show-stoppers, big issues?